Bibcode
Russell, D. M.; Curran, P. A.; Muñoz-Darias, T.; Lewis, F.; Motta, S.; Stiele, H.; Belloni, T.; Miller-Jones, J. C. A.; Jonker, P. G.; O'Brien, K.; Homan, J.; Casella, P.; Gandhi, P.; Soleri, P.; Markoff, S.; Maitra, D.; Gallo, E.; Cadolle Bel, M.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 419, Issue 2, pp. 1740-1751.
Fecha de publicación:
1
2012
Número de citas
25
Número de citas referidas
25
Descripción
We present optical monitoring of the black hole candidate XTE J1752-223
during its 2009-10 outburst and decay to quiescence. The optical light
curve can be described by an exponential decay followed by a plateau,
then a more rapid fade towards quiescence. The plateau appears to be due
to an extra component of optical emission that brightens and then fades
over ˜40 days. We show evidence for the origin of this optical
'flare' to be the synchrotron jet during the decaying hard state, and we
identify and isolate both disc and jet components in the spectral energy
distributions. The optical flare has the same morphology and amplitude
as a contemporaneous X-ray rebrightening. This suggests a common origin,
but no firm conclusions can be made favouring or disfavouring the jet
producing the X-ray flare. The quiescent optical magnitudes are B≥
20.6, V≥ 21.1, R≥ 19.5, i'≥ 19.2. From the optical outburst
amplitude we estimate a likely orbital period of <22 h. We also
present near-infrared (NIR) photometry and polarimetry and rare mid-IR
imaging (8-12 ?m) when the source is nearing quiescence. The fading jet
component, and possibly the companion star, may contribute to the NIR
flux. We derive deep mid-IR flux upper limits and NIR linear
polarization upper limits. With the inclusion of radio data, we measure
an almost flat jet spectral index between radio and optical;
Fν∝ν˜+0.05. The data favour the
jet break to optically thin emission to reside in the IR, but may shift
to frequencies as high as the optical or UV during the peak of the
flare. Based on observations collected at the European Southern
Observatory, Chile, under ESO Programme ID 086.D-0610, the William
Herschel Telescope operated on the island of La Palma by the Isaac
Newton Group in the Spanish Observatorio del Roque de los Muchachos of
the Instituto de Astrofísica de Canarias and the Faulkes
Telescopes at Haleakala, Maui, USA and Siding Spring, Australia.